Since the inaugural race in 1851, the America’s Cup has been on the leading edge of sailing technology. But it wasn’t until 1983, when the Australians unveiled a radical new “winged keel”, that technology became the dominant force in America’s Cup racing.
Following the Australians’ unprecedented win over the Americans—who had won every consecutive America’s Cup until that point—technological advances have been at the heart of the America’s Cup, with teams using cutting-edge materials and radical designs to gain the upper hand over their competitors.
In 2013 those designs reached new heights in the form of two new boats—the AC72 (72 feet) and a scaled-down version, the AC45 (45 feet), which was used for the preliminary training and racing. Using innovative wing sail designs and hydrofoils, the yachts were able to achieve almost three times the wind speed, skipping along at a clip of up to 47 knots, or 55 kilometres per hour. If they were on the roads instead of water, older Bermudians would complain non-stop about them.
Boat Speed
The speeds reached by the AC72 and AC45 defi ed all predictions, and at fi rst glance, the numbers appear to defy logic as well. Instead of traditional cloth sails attached to a mast, the America’s Cup yachts used fixed rigid wing sails. This enabled the boats to exploit the Bernoulli principle—the same thing that makes planes fly—by creating a difference in pressure on either side of the sail, generating lift. In simpler terms, a wing that is parallel to the ground creates upward lift, while a perpendicular wing creates forward lift, or in this case forward motion through the water.
But moving through the water is a problem in itself. The AC72 weighed seven tonnes. To get around the challenge of pushing all that boat through the water, the yachts used hydrofoils that extended beneath them, enabling them to sail without any part of the boats’ hull in the water.
After reaching around 20 knots the boats pop up out of the water so the weight of the boat is carried on the carbon fi bre foils, which can take up to 15 tonnes of pressure. By being entirely out of the water, the reduction in drag lets the boat go between 10 and 15 per cent faster.
Crew Gear
Gone are the days when men like Dennis Connor could casually guide their boats to victory without breaking a sweat. Today’s America’s Cup sailors have more in common with a Formula 1 driver than a Sunday beer can racer. The job is more difficult and dangerous, than ever before.
The men sailing these boats range from highly skilled technicians to finely tuned athletes, and need as much protection as possible should everything go south. Along with personal floatation devices, each crewmember must wear crash helmets and body armor, and carry bottled air in case they are trapped underwater. They also carry personal locator beacons and knives to cut away rigging if they become entangled.
